1. Field of the Invention
The present invention relates to an electronic seal.
2. Description of the Prior Art
A conventional electronic seal, such as disclosed in U.S. Pat. No. 7,597,253, U.S. Pat. No. 6,747,558 or U.S. Pat. No. 7,044,512, is mainly used to seal a cargo or the like. They mainly include a circuit to determine whether a seal is severed or not.